. >> we remember this president was very, very critical of the last president, george w. bush for taking action without u.n. approval in iraq. would he work unilaterally without u.n. approval? >> that's a big question and hotly debated in the white house is what to do in terms of the united states. russia has a veto at the u.n. russia has blocked any measures to punish syria up to this time. there is consideration of trying to go back to the u.n., trying to convince the russians that syria crossed a line here, but that is highly unlikely that russia would go along. in the event they don't, i am told by senior officials that the u.s. would not go alone. this would have to be a coalition effort, if not with the u.n., with other al eyes, nato and others. >> president obama's aids with a former complicate, this is a problem from hell. he will be more on "this week." >> all right, dan, turn now to the devastating diagnoses that silenced linda ronstadt. she's had a decade-long battle with parkinson's disease ♪ i've looked all my life >> he's been singing all her life, but now